The General Medical Council has warned that the medical profession is at "crunch point".
Responding, Liberal Democrat leader Vince Cable said:
"The GMC report shows there has been a vast increase in A&E attendances, while the number of doctors has barely grown. A sensible strategy of switching demand from A&E to GP surgeries can't work if GPs are unable to cope because of funding and recruitment pressures.
"The Conservatives must increase spending on the NHS immediately, but in an honest way. This requires strong politics, which is why the Liberal Democrats are open and unapologetic about the need to put a penny on income tax for the NHS."